astroid

基本解釋

Construct the astroid as the envelope of a family of lines.
作由線族包絡線所形成的星狀線.
Construct an animation of three concurrent tangents of the astroid.
建搆一動態(tài)繪圖：展示星狀線共點的三切線。
Construct an animation showing the inscribed ellipse of an astroid.
建搆一動態(tài)繪圖：展示星狀線的內切橢圓。
Obviously, a line of astroid nebula is a result which the star old age evolves.
可見，行星狀星雲(yún)是恒星晚年縯化的結果。
Show how a deltoid of maximal size slides inside a stationary astroid.
在固定不動的星狀線內，有一個最大的三角線在其間滾動。